Entwicklung eines Referenzbauteils zur Prüfung von dickwandigen Großgussbauteilen

Research output: ThesisDiploma Thesis

Authors

Abstract

This thesis deals with the development of a reference component with the characteristic wall thickness and properties of a wind turbine hub, to obtain information regarding the properties of thick-walled castings. With existing equipment at the chair of mechanical engineering and a newly designed clamping device, this developed component should be tested with reasonable expense. It should be possible to influence the quality of the component through specific design and casting procedures. In order to obtain comparative values for the development of this reference component, structure-mechanical analysis of the hub was evaluated with the commercial FE code Abaqus. Parameters, such as the highly stressed volume and the relative stress gradient, were used in this evaluation. Due to various loads and stress situations, values for the highly stressed volume in range of 1200-1800 mm3 and values for the relative stress gradient in range of 0,08-0,1 mm−1 could be defined as parameters which can be compared with the simulation results of the reference component. In this way the geometry of the component was iteratively adjusted and improved. By using micro-modeling techniques in casting simulations, local microstructural properties could be estimated. In ductile cast iron graphite nodules per square millimeter can be numerically determined. To compare the casting simulations with the structure of the hub, microsections were made, analyzed and validated. The areas of highest stresses show a number of graphite nodules between 40 to 70 nodules per square millimeter. Due to this simulation results the geometry of the reference component could be further adjusted. To test the component, a clamping device was designed. This allows a 4-point bending test with both, pulsating and alternating load. In the course of the design of this clamping device, calculations were carried out for the clamping forces as well as for the deflection of the component.

Details

Translated title of the contributionDevelopment of a reference component for the testing of large thick-walled cast components
Original languageGerman
QualificationDipl.-Ing.
Supervisors/Advisors
Award date4 Apr 2014
Publication statusPublished - 2014